1. Field of the Invention
This invention relates to a keyboard device capable of changing an inclination angle of a main body and optimizing the touch at a key when a key touch operation is performed.
2. Description of the Related Art
FIG. 12 is a perspective view for showing a part at a rear side of a prior art keyboard device 50.
This keyboard device 50 is constituted of a main body 51 and an adjuster member 52. Rectangular box-shaped notches 53 are formed at both longitudinal ends (only one end is shown in the figure) of the rear surface of the main body 51, and the adjuster member 52 is stored in the notch 53. The adjuster member 52 is formed with a shaft 52a extending in a longitudinal direction of the main body 51 at one end thereof. The shaft 52a is further formed with supporting protrusions 52b, 52b axially protruded, wherein the supporting protrusions 52b, 52b are inserted into two bearing holes (not shown) at positions within the notch 53 to which the shaft 52a oppositely faces and pivotally supported there.
With the above arrangement, an inclination angle of the main body 51 can be adjusted. When it is not needed to increase the inclination angle of the main body 51, the adjuster member 52 is stored in the notch 53 so as not to be projected out of the bottom surface 51a. In addition, when the inclination angle of the main body 51 is increased, the adjuster member 52 is turned out of the notch 53 around a fulcrum point of the shaft 52a, thereby it is protruded out of the rear surface 51a and then the adjuster member 52 is raised as shown by a dotted line in FIG. 12.
However, this kind of keyboard device of the prior art indicated by the keyboard device 50 has the following drawbacks.
That is, in the case of the aforesaid keyboard device 50, the adjuster member 52 is turned from the bottom surface 51a of the main body 51 around the horizontal shaft 52a to its raised attitude, so that when the keyboard device 50 is mounted in slant form under a state in which the adjuster member 52 is protruded, there is a possibility that the adjuster member 52 is turned around the shaft 52a by own weight of the keyboard device 50 and by a manual pressing force and the state in which the adjuster member 52 is protruded is not stable.
Further, in the case where the adjuster member 52 is raised up from the bottom surface 51a at the main body 51, it is needed that the free end of the adjuster member 52 is held by fingers and the adjuster member 52 is turned in a direction moving away from the bottom surface 51a. However, in order to perform the aforesaid raising-up operation while bringing the fingers around the rear side of the keyboard device 50, its operation is quite hard to perform and it is quite difficult to set the keyboard device to its inclined attitude.
In addition, the aforesaid keyboard device 50 sometimes shows the case where its inclination angle cannot be changed in a stepwise manner and an operator cannot necessarily operate keys under the most suitable inclination angle.
The present invention has been invented to solve the aforesaid problems and it is an object of the present invention to provide a keyboard device in which an operator can perform a key operation positively even if a horizontal place cannot be secured, setting of the inclination attitude can be easily attained and the inclination angle can be changed stepwise.
The present invention provides a keyboard device in which an adjuster member arranged at a rear surface of a main body having operation keys at its front surface and installed to be freely protruded from the rear surface is installed and a mounting attitude of the main body is set to a predetermined angle when the adjuster member is protruded, wherein the rear surface of the main body is formed with a notch, the adjuster member is rotatably supported in the notch, the adjuster member can be turned between one attitude in which it is stored in the notch and another attitude in which it is protruded out of the rear surface.
In this case, it is preferable that a turning centerline of the adjuster member is extended from within the notch toward an opening side of the notch at an angle inclined against the rear surface of the main body, one end of the adjuster member in its longitudinal direction is a supporting side rotatably supported and the other end of the adjuster member in its longitudinal direction is a protruding end protruded out of the notch when it is turned, the turning centerline of the turning operation is positioned at the one end side and crossed with a direction extending from the one end to the other end.
Pivot supporting of only one end side composed of the turning centerline with the aforesaid means enables the adjuster member to be changed in two types of attitudes, i.e. one attitude in which the adjuster member is stored in the notch at the time of its turning and the other attitude in which the adjuster member is protruded out of the rear surface of the keyboard device.
In the present invention, it is preferable that the notch is made to have a large depth size measured from the rear surface at a portion where the supporting side of the adjuster member is rotatably supported and its depth size is made to be small as it is spaced apart from the portion where it is rotatably supported, and a thickness size of the adjuster member in a direction to which the turning centerline extends shows a thick size at the supporting side and shows a thin size as it is directed toward the protruding end.
With the aforesaid means, when the adjuster member is placed at an attitude in which it is turned and protruded out of the notch, the protruding end of the adjuster member always becomes the lower-most end and an inclination angle of the main body is changed.
In the present invention, it is preferable that the inner surface of the notch is a concave curved surface including arcs with a plurality of locations on the turning centerline being applied as centers, the side of the adjuster member opposing against the inner surface of the notch is of a shape in which it is slid on the concave curved surface with little clearance during its turning operation, and when the adjuster member is stored in the notch, the side of the adjuster member opposite to the opposing side is of a surface shape where it is positioned on the substantially same location as that of the rear surface.
With the above arrangement, even in the case where the key operation is carried out under an attitude in which the adjuster member is stored in the notch, its stability in operation is not damaged. In addition, it is possible to keep the shape of the notch to a minimum size by forming it into a shape in which the adjuster member slides at the concave curved surface with little clearance, resulting in an arrangement of other members installed inside the main body free from restriction.
In addition, it is preferable in the present invention that there is provided lock means for locking between the main body and the adjuster member under a state in which the protruding end is protruded out of the rear surface. With the above arrangement, it is possible to securely hold the inclination angle of the main body in and to prevent trouble of the key operation while the adjuster member is turned at the time of key operation.
In addition, it is preferable in the present invention that there is provided lock means for locking between the main body and the adjuster member under a state in which the adjuster member is stored in the notch. With the above arrangement, the adjuster member is prevented from freely flown out of the main body in the case where the main body is lifted up, for example.
In addition, the present invention may be provided with lock means for locking between the main body and the adjuster member under a state in which the protruding end is protruded out of the rear surface, a state in which the adjuster member is stored in the notch and an attitude at least in one of the states above.
With the above means, each of the operators performing a key operation can use the keyboard device while inclining it at the most suitable angle. In addition, in the case where two adjuster members are arranged at two locations, that is, both ends of the rear surface of the main body, for example, each of one attitude where one adjuster member protrudes and the other attitude where the other adjuster member protrudes is independently set to enable the main body to be stably mounted even if the space where the main body is installed is not necessarily a horizontal surface, and so a secure key operation becomes possible.
Further, it is preferable in the present invention that the adjuster member is provided with a shaft, bearing holes through which the shaft passes are opened in the notch, the main body is provided a resilient member for resiliently pressing itself against the outer circumference of the shaft under a state in which the shaft is inserted into the bearing holes, the shaft and the resilient member are fitted to each other to form the lock means.
The notch is formed at the outer circumferential surface of the shaft and the resilient member is fitted to the notch, for example, thereby the adjuster member is held at a predetermined position when the adjuster member is turned.
In addition, it is preferable in the present invention that the resilient member resiliently presses the shaft passed through the bearing holes and this resilient member prevents the shaft from being pulled out of the bearing holes.
Additionally, it is preferable in the present invention that the adjuster members are arranged at at least two locations in the rear surface of the main body. For example, in the case where two adjuster members are arranged at two locations, it is preferable that they are installed at both ends of the rear surface of the main body.